Abstract

Exudates were obtained  from the African pear and mango trees and also from unripe plantain and banana fruit bunches, and their keeping and functional properties as industrial raw materials were determined. Exudation from the trees was carried out by making an incision on the tree bark, while those from the unripe fruit were collected from the cutting made to severe the bunch from the stock during harvesting. Results obtained showed a yield of 20.8 and 18.6 g/tree of African pear and mango respectively after 24 h of tapping and 8.6 and 10.2 ml/kg for plantain and banana per bunch, respectively. The yield of exudates from the plantain and banana trunks was 158.5 and 120.2 ml/tree,respectively. Other results were pH: African pear, 5.35; mango, 6.05; plantain, 4.93 and banana, 6.44; phenol contents: African pear, 15.67 mg/kg; mango, 15.97 mg/kg;plantain, 12.54 mg/kg and banana, 9.40 mg/kg; tannin content: African pear, 0.32%;mango, 0.28%; plantain, 0.32%, and banana, 0.46%. The exudates were soluble in polar solvent and sparingly soluble in organic and non polar solvents and all of them had a good amount of cations for cell growth present such as calcium, potassium, magnesium and sodium. They can also be preserved using well known food preservatives. From the results, it was deduced that the exudates may become raw materials for pharmaceutical and paint industries if the machinery for their collection and preservation are established.

Key words: Characterization, exudates, tropical trees, unripe fruits.